2D Phased Subarray MIMO Radar Layout for Grating Lobe Cancellation
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Solution Overview
Problem
Conventional MIMO radars face challenges in arranging multiple antennas effectively at higher frequencies due to increased integrated circuit size, leading to degraded resolution and performance, especially when spacing between antennas is not optimal.
Innovation Solution
A two-dimensional phased subarray MIMO radar system is developed, where transmission and reception arrays are arranged with increased spacing between phased subarrays, and RF beamforming is used to cancel grating lobes, allowing for improved sensitivity and resolution while accommodating higher frequency signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the spacing between antennas is increased to improve resolution, then spatial resolution is improved, but grating lobes occur and sensitivity is degraded
Solution Approach 1:
The antenna array is divided into multiple subarrays with different aperture sizes. By segmenting the array into subarrays (e.g., first subarray with smaller aperture, second subarray with larger aperture), the system can increase overall spacing for resolution while using phase shifting to control and eliminate grating lobes, thus maintaining sensitivity.
Solution Approach 2:
Phase shift parameters are dynamically adjusted for each subarray to control beam forming. By changing the phase shift parameters, the system can cancel grating lobes that occur due to increased spacing, thereby maintaining both resolution and sensitivity.
2Measurement precision
If higher frequency signals are used to improve spatial resolution, then spatial resolution and information transfer are improved, but the integrated circuit size becomes larger making antenna arrangement more difficult
Solution Approach 1:
The system segments the antenna array into multiple subarrays, each with its own phase shifter. This segmentation allows the use of higher frequency signals for improved resolution while managing the complexity of integrated circuits by distributing phase control across multiple smaller subarrays rather than one large array.
Solution Approach 2:
The patent introduces a new dimension of control through phase shift parameters for each subarray. This additional degree of freedom allows the system to manage the complexity of high-frequency integrated circuits while maintaining the benefits of higher frequencies for resolution.
3Measurement precision
If multiple antennas are arranged based on half-wavelength spacing to minimize interference, then spatial resolution is improved, but the hardware size becomes larger
Solution Approach 1:
By dividing the antenna array into multiple subarrays with different aperture sizes, the system can achieve the resolution benefits of multiple antennas while reducing the overall hardware footprint. The segmented structure allows more efficient space utilization compared to a uniform half-wavelength spaced array.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system achieves enhanced sensitivity and resolution by expanding antenna aperture and canceling grating lobes, enabling efficient operation with higher frequency signals and meeting user technical requirements through adjustable antenna configurations.
Implementation Method 1
a plurality of transmission antennas TA1 to TAm configured to emit transmission signals TS that are orthogonal to each other towards a target
Implementation Method 2
a plurality of reception antennas RA1 to RAm configured to receive reflected signals RS, which are reflected from the target
Implementation Method 3
RF beamforming is used to cancel grating lobes
Implementation Method 4
cancelling the grating lobes that occur during the process of increasing the spacing between the plurality of phased subarrays through RF beamforming
Data Source
AI summary
A two-dimensional phased subarray MIMO radar apparatus includes a transmission array and a reception array. The transmission array is configured to emit transmission signals, which are orthogonal to each other, towards a target object and extends in a first direction. Moreover, the transmission array includes a plurality of transmission phased subarrays. The reception array is configured to receive reflected signals, which are reflected from the target object, among the emitted transmission signals and extends in a second direction intersecting the first direction. Moreover, the reception array includes a plurality of reception phased subarrays. Each of the plurality of transmission phased subarrays includes a plurality of transmission antennas. Each of the plurality of reception phased subarrays includes a plurality of reception antennas. A first transmission phased subarray and a second transmission phased subarray are adjacent transmission phased subarrays among the plurality of transmission phased subarrays. A spacing from an end of the first transmission phased subarray in the first direction to an end of the second transmission phased subarray in the first direction is a first spacing. The first spacing is greater than or equal to an aperture of each of the plurality of transmission phased subarrays.